OBJECTIVE: Our purpose was to compare the practice patterns and outcomes of physicians delivering in our institution to identify risk factors and management techniques that could explain the differences in individual cesarean section rates. STUDY DESIGN: We retrospectively reviewed detailed computerized delivery records (n = 16,230) collected from May 16, 1988, to July 30, 1995. We excluded physicians who had <100 deliveries at our institution during the study period. The physicians were divided into two groups depending on whether their individual cesarean section rates were greater than (control group) or less than 15% (target group). Various cesarean section rates, risk factors for abdominal delivery, labor management techniques, and neonatal outcome parameters were calculated for each group. The cesarean section rates of the two groups were analyzed by year to assess changes. RESULTS: As expected by study design, the overall cesarean section rate was markedly different between the two groups (13.8% vs 23.8%). In addition, the primary, repeat, primigravid, and multiparous cesarean section rates were all lower for the target group. The rates of cesarean section for fetal distress (1.5% vs 3.3%) and cephalopelvic disproportion (5.3% vs 8.5%) were also significantly less in the target group. The rates of breech presentation, third-trimester bleeding, and active herpes cesarean sections were not lower. The control group had more postterm (8.6% vs 14.7%) and >4000 gm infants (12.0% vs 13.7%) but similar numbers of low birth weight, multiple gestation, and preterm infants. The target group used more epidural anesthesia, oxytocin induction, and trial vaginal births after cesarean delivery and more successful trial vaginal births after cesarean sections. Over the study period the cesarean section rate in the target group remained unchanged, whereas it steadily declined in the control group. CONCLUSIONS: Individual physician's lower cesarean sections are primarily obtained by labor management and attempting vaginal birth after cesarean delivery. These practice patterns did not appear to lead to any increase in perinatal morbidity or mortality. Efforts to lower cesarean section rates of individual practitioners should focus on the areas of fetal distress, cephalopelvic disproportion, and repeat cesarean section.